A closed winnowing system located below a husking device is conventionally well-known, as disclosed in Japanese Patent Publications No. 21188 (1963) and No. 50187 (1977), for example.
FIG. 21 shows such prior art apparatus in detail. In accordance with the prior art, a closed winnowing system is located below a husking unit D including a grain hopper 23 and husking rolls 20 and 21. In the winnowing system, two outlets are provided below the winnowing room A′. One is a first outlet 24 where winnowed grains (including husked grains and unhusked grains) fall, and the other is a second outlet 25 where lightweight particles such as fruitlessness and crashed grains being blown up fail.
Further, a third outlet 26 where extremely lightweight hulls being blown away fall is provided at a reverse position of the blowing room B with respect to the winnowing fan F.
After winnowing, the winnowed grains, lightweight particles and hulls are sorted into three outlets: “the first outlet 24 where winnowed grains fall”; “the second outlet 25 where lightweight particles (fruitlessness, crashed grains and the like) being blown up fall”; and “the third outlet 26 where hulls being blown away fall”.
However, such sorting method has been available at a time when lightweight crashed grains and the like fallen from the second outlet 25 were taken seriously as feeding stuff for livestock and poultry. In recent years, the necessity of “the second outlet 25 where lightweight particles being blown up fall” has been decreased.
Further, in this manner, a flow of winnowing wind must be guided so as to sort winnowed grains and lightweight particles between the first outlet 24 and the second outlet 25. As a result, the winnowing wind can not set to be strong. Accordingly, a separation capacity is decreased, so that a husking process capacity of the husking unit D is also decreased whereby a malfunction in which a husking and winnowing process of large capacity can not be executed at a short time has been occurred.
In a view of mentioned above, an object of the present invention is to provide a closed grain winnowing system constituted so as to sort winnowed grains and others into only two outlets of “a winnowed grain conveyor” and “a hull conveyor” after the winnowing.